Multi-stage drag pump



April 25, 1967 Filed June 4, 1965 H. M INNES MULTI-STAGE DRAG PUMP 5Sheets-Sheet 1 INVENTOR. -//UG// Ma AVA/5s ATTORNEYS April 25, 1967 H.Ma INNES 3,315,607

MULTI-STAGE DRAG PUMP Filed June 4, 1965 5 Sheets-Sheet 2 4& T

INVENTOR. 1 /06 MC A/Ms's ATTORNEYS April 25, 1967 Ma INNES 3,315,607

v MULTI-STAGE DRAG PUMP Filed June 4, 1965 INVENTOR. 6 06 M4C/A/A/65ATTORNEYS 5 Sheets-Sheet 5 April 25, 1967 'H. M lNNES MULTI-S'I'AGE DRAGPUMP 5 Sheets-Sheet 4 Filed June 4, 1965 INVENTOR. Huey /l /2/c //VA/5Mm, 7% @9 V ATTORNEYS April 25, 1967 H. M INNES MULTI-STAGE DRAG PUMP 5Sheets-Sheet 5 Filed. June 4, 1965 INVENTOR. 6 064 M46 Amss y 7ATTORNEYS United States Patent 3,315,607 MULTI-STAGE DRAG PUMP HughMacinnes, Richmond Heights, Ohio, assignor to TRW Inc., Cleveland, Ohio,a corporation of Ohio Filed June 4, 1965, Ser. No. 461,415 12 Claims.(Cl. 103-108) This invention relates generally to a so-called reentrycompressor or fluid pump sometimes referred to as a drag pump and whichis particularly characterized by a rotor having a central hub with adisk-shaped body and peripheral vanes on opposite axial sides thereofwith an axial or radial through passage means formed in the diskshapedbody either with or without pumping vanes for interconnecting andstaging the oppositely disposed vanes in series flow relation.

Fluid pumps which are commonly known as drag pumps, offercharacteristics in a centrifugal compressor which fall somewhere betweenthose of the positive displacement pump and the centrifugal pump. Thismeans the single stage pump produces a medium pressure at the outputwhen running at a medium speed, as compared with either of the other twotypes. Because of those characteristics and the fact that it is not apositive displacement pump, there are many applications where such apump should do a good job and be economically feasible-as compared tothe other two types.

In some instances, it is desirable to have a discharge pressure in thesame magnitude as the positive displacement pump while running in thesame speed magnitude. In accordance with the principles of the presentinvention, such objective can be accomplished by placing additionalstages on the drag pump without increasing the size and complexity ofthe pump by the means of internal passaging such as a passage formed byholes or apertures extending axially through the disk of the rotor andallowing the fluid to pass from a first stage on one side of the rotorto a second stageon the other side of the rotor. .By virtue of suchprovision, the stages are interconnected and staged in series. It willbe apparent that the staging arrangement thus contemplated would applyto drag-type turbines as well as to compressors since the generalstructural arrangement would be similar in both.

It is an object of the present invention, therefore, to provide acompressor means aifording discharge pressures in the same magnitude aspositive displacement pumps, but with a compressor means running in thesame speed magnitude as a drag pump.

Another object of the present invention is to provide a so-calledreentry-type compressor wherein multiple stages are interconnectedthrough internal passages formed in the body of the rotor.

Another object of the present invention is to provide a stagingarrangement for a fluid pump which avoids increase in size andcomplexity of the pump construction.

Many other features, advantages and additional objects of the presentinvention will become maifest to those versed in the art upon makingreference to the detailed description which follows and the accompanyingsheets of drawings in which a preferred structural embodiment of areentry-type compressor is shown by way of illustrative example.

On the drawings:

FIGURE 1 is an end elevational view of a reentry compressor provide inaccordance with the principles of the present invention;

FIGURE 2 is an end elevational view from an end opposite that shown inFIGURE 1 of the reentry compressor of the present invention;

FIGURE 3 is a cross-sectional view taken on line III-I11 of FIGURE 1;

FIGURE 4 is an elevational view of the inlet cover taken on the plane ofline IV-1V of FIGURE 3;

FIGURE 5 is an elevational view of the inside of the outlet cover takenin the direction of the plane of line VV of FIGURE 3;

FIGURE 6 is a fragmentary cross-sectional view taken on line VIVI ofFIGURE 5;

FIGURE 7 is an elevational view showing additional details ofconstruction of the rotor;

FIGURE 8 is a fragmentary cross-sectional view taken on line VIIIVIII ofFIGURE 7;

FIGURE 9 is a fragmentary cross-sectional view taken on line IXIX ofFIGURE 5;

FIGURE 10 is a cross-sectional view of an alternative form ofconstruction wherein the intercommunication be tween the stages isformed by axial through holes in the hub of the rotor;

FIGURE 11 shows yet another embodiment of the present invention whereinthe rotor is formed out of a thin sheet material such as sheet metal andwherein the intercommunication between the stages takes the form ofradial openings including centrifugal vane pumping means for assistingthe pumping action achieved by the pumping apparatus; and

FIGURE 12 is a fragmentary cross-sectional view taken generally on lineX[IXII of FIGURE 11.

As shown on the drawings:

The pump of the present invention comprises a reentry compressor showngenerally at 10. An inlet cover 11 has a flange 12 formed with aplurality of apertures 13 for receiving fastening means such as screws14 for engaging correspondingly threaded openings 16 provided in aflange 17 of an outlet cover 1 8. Thus, the inlet cover 11 and theoutlet cover 18 may be fastened together in order to form a casing forthe compressor.

The inlet cover 11 is particularly characterized by a centrally disposedboss 19 having a bore 20 in which is received a sleeve 21 forming a pairof axially spaced races 22, 22 in which to journal a shaft 23. The shaft23 is characterized by a pair of axially spaced grooves 24, 24 arrangedto be disposed in register with the races 22, 22 and a plurality ofshiftable elements such as hearing balls 26 are disposed between theraces 22 and 24. The shaft 23 extends outwardly of the casing and hasconnected thereto a pulley 27, thereby to provide a connection to amotive source. The inner end of the shaft 23 is connected as at 28 to arotor shown generally at 29.

As shown in FIGURE 2, the inlet cover 11 has formed on the outside facethereof a plurality of radially extending circumferentially spacedstrengthening ribs 30 and there is also provided a pair of spaced bosses31, 31 which may be used as pad mounts for the pump. At the upperportion of the inlet cover 11, there is formed a boss 32 having a flatface intersected by an inlet opening 33, to which face 32 may beconnected an inlet adapter for connecting the inlet 33 to a source offluid to be pumped.

Referring now to FIGURE 4, the inner face of the inlet cover 11 is shownas being characterized by a semitoroidal circumferentially extendingpumping duct 34 having an inner wall 36 and an outer wall 37, both ofwhich are arranged in generally concentric relation to the axis of thepump, thereby to form a pumping duct which extends circumferentiallyfrom an end portion 38 to an opposite end portion 39. The end portion 38is arranged just adjacentthe inlet opening 33 and at the end portion 39,the inside face of the inlet cover 11 is characterized by a radiallyinwardly extending discharge passage 40.

The outlet cover 18, as shown in FIGURE 1, has a plurality ofstrengthening ribs 41 which extend radially outwardly from a center boss42. On opposite sides of the boss 42 there is provided a pair of bosses43, 43 each having a flat face 44, thereby to provide additional padmounting means for the compressor.

At the upper portion of the outlet cover 18, there is outlet cover 18 isshown as being characterized by the formation therein of a semi-toroidalrecess 49 having an outer wall 50 and an inner wall 51, bothconcentrically disposed relative to the pump axis. The recess 49'extendscircumferentially from an end portion 52 disposed immediately adjacentthe outlet opening 43 and the recess 49 extends to the opposite endportion 53. At the end por- .tion 53, there is formed a radiallyinwardly extending inlet passage 54 which intersects an annular groove56 spaced outwardly of a center boss 57.

Referring now to FIGURE 7 in conjunction with FIG- URE 3, it may benoted that the rotor 29 may conveniently comprise two separate partsfastened together to form a single disk-shaped article, the two partshaving a line of juncture shown at 66. The rotor 29 has a hub 61 inwhich the shaft 23 is connected as at 28 and a diskshaped body extendsradially outwardly from the hub 61 terminating in an enlarged peripheralportion 62.

The rotor 29 is particularly characterized by having formed thereinsemi-toroidal circumferentially continuous vane ducts on opposite axialsides thereof which are adapted to be disposed between the pumping ductsor recesses 34 and 49 respectively. In this connection, note that oneface of the rotor 29 has a circumferentially extending recess formedtherein which is identified at 63 including an inner wall 64 and anouter wall 65. That recess 63 confronts the recess 34 formed in theinlet cover 11.

In like manner, the other face of the rotor 29 has a semi-toroidalrecess 66 formed therein having an outer wall 67 and an inner wall 68and which recess 66 confronts the pumping duct 49.

In the course of fabrication, the rotor 29 is provided with a pluralityof slots which extend transversely of the corresponding recesses 63 and66 and which slots are more specifically identified in FIGURE 7 at 69.Received within each slot 69 is a vane 70, thereby disposing a pluralityof vanes 70 in an annular row in circumferentially spaced relation sothat all of the vanes 70, in the respective recesses 63 and 66, form aplurality of impeller pockets 71 adapted to be moved upon rotation ofthe impeller 29 within the casing formed by the inlet cover 11 and theoutlet cover 18.

It may also be noted that the outlet cover 18 is particularlycharacterized by an axially extending portion 72 providing an inneraxial wall 73 disposed adjacent the outer periphery of the rotor 29.

In accordance with the principles of the present invention, theoppositely disposed pumping ducts or runners 34 and 49 and theoppositely disposed vanes of the rotor 29 are interconnected for seriesstaging relationship by means of a passage extendingthrough thedisk-shaped body portion of the rotor 29.

It is contemplated by the present invention that the oppositely disposedvanes of the rotor be interconnected and staged in series flow relation.Such interconnection can be accomplished in different ways.

Referring, for example, to the trated in FIGURE 10, there is shown acasing 11a having an inlet 33a so that fluid entering the inlet 33a willbe impelled by a plurality of impeller pockets 71a and vanes 70a on oneside of a rotor shown generally at 29a is pressurized through a runneror pumping duct 34a, passing out of a first stage outlet shown at 49a.The fluid then passes through the hub portion of the rotor 29a and inthis embodiment of the invention, the rotor is particularlycharacterized by axial through openings 74a. After passing through theopenings 74a the fluid enters an inlet passage shown at 54a, whereuponit is acted upon by the impeller pockets and vanes on the other side ofform of the pump illusthe rotor 29a through the pumping duct or runner49a and is then discharged through an outlet opening 48a.

In the form of the invention illustrated in FIGURES 11 and 12, the pumpis of the same general organization and like reference numerals are usedwith the suffix b to designate like parts. In this form of theinvention, however, the rotor is shown generally at 291; and mayadvantageously be constructed of a thin material such as sheet metalshaped to form a toroidally shaped article. For example, the rotor wall1% suitably fastened, for example, by spot welding or the like to a hubmember 1.01 carried on a shaft 23b.

The radial wall 1% terminates in an axially extending wall 162 spacedradially outwardly of the shaft 23b and arranged in general concentricrelation to the axis of rotation thereof. The axial wall 192 isparticularly characterized by having a plurality of circumferentiallyspaced struck-out pumping vanes 103 which in this form of the inventionare struck-out to be shaped and arranged in outwardly projectingrelation relative to corresponding openings 104. Thus, fluid dischargedby the first stage through a first stage outlet 4% will pass through theopenings 104 and will be assisted by the pumping action of the vanes 103as the fluid the second stage. Thus, the fluid will enter the secondstage inlet shown at 54b.

The axial wall 1(32 terminates in a second radial wall 106 which isoffset in an axial direction in order to form a generallysemi-toroidally shaped recess .107 and the rotor terminates in. an outerperipheral edge 168.

In order to provide the second stage ofthe rotor, a separate piece ofmetal may be shaped to provide an annular trough-shaped article which issemi-toroidal in the cross-section and which is shown at 1%9. Thearticle 109 may be connected in firm assembly to the correspondinglyshaped portion of the main rotor by means of spot welding or shown at11%). Thus, the completely assembled rotor provides a toroid in whichthe vanes may be 'mounted for accomplishing the pumping action describedin connection with the other forms of the pumping apparatus hereindescribed. The outlet of the pump is shown at 4811. i

In the form or the invention disclosed in FIGURES 1 9, the openings "74constitute four circumferentially spaced passages having an irregularconfiguration shaped to develop the attributes of an airfoil or a fan inorder 7 to develop a pumping capacity. Thus, as the fluid passes throughthe openings 74, it is additionally impelled by. configuration, therebyIn operation, fluid enters the inlet 33 (or 33a or 331;)

and is impelled by the impeller pockets 7 1 and the vanes 7 9 on oneside of the rotor 29 through the pumping duct 34 whereupon the fluid ispassed through the discharge passage 40 and thence through the internalpassages 74 formed in the disk portion of the rotor 29.. The fluid thenenters the inlet passage 54 (or 54a or'54b) andis impelled by theimpeller pockets and the vanes on the other side of the rotor 29 throughthe pumping duct 49 and the fluid is then discharged through the outletvopening 48. By virtue of such provision, it is possible to have adischarge pressure in the same magnitude as a positive displacementpump, while running in the speed magnitude of a so-called drag pump.

Although other modifications might be suggested by those versed in theart, it should be understood that I wish to embody within the scope ofthe patent warranted hereon all such modifications as reasonably andproperly come within the scope of my contribution to the art.

I claim as my invention:

1. A fluid compressor of the drag type comprising,

casing means forming two pumping chambers constituting a first stage anda second stage, I

2% has a radially outwardly extending is impelled from the first stageto.

other suitable fastening technique as V each having an inlet and anoutlet, and an impeller rotor journaled for rotation in said casingmeans,

and having a centrally disposed hub, a disk extending radially outwardlytherefrom, and oppositely disposed vanes outwardly of correspondinglyopposite sides of said disk for acting on fluid in each respective stageof said two pumping chambers, and an internal passage formed in andextending axially through said disk of said rotor and interconnectingsaid outlet of said first stage with said inlet of said second stage. 2.A fluid pump of the drag-type comprising, first and second cover memberstogether forming a pump casing, one of said cover members having aninlet opening formed therein for connection to a source of fluid to bepumped,

said one of said cover members having formed on the inner face thereofan annular vane duct connected to said inlet and having a dischargepassage directed radially inwardly thereof, the other of said covermembers having formed therein on the inner face thereof an annular vaneduct and having an inlet passage extending radially inwardly thereof andan outlet opening for connection to a point of utilization, a rotor insaid casing having a drive shaft connected thereto and said drive shaftprojecting out of said casing for connection to a source of motivepower, said rotor including annular recesses disposed on opposite axialsides of said rotor for registry with said vane ducts, said rotor havinga plurality of circumferentially spaced slots each extending across acorresponding one of said annular recesses, and a vane in each slot toform with said recesses a plurality of impeller pockets, and axialpassage means formed in said rotor disposed to extend axially betweensaid discharge passage and said inlet passage interconnecting said vaneducts in series staged flow relation. 3. A reentry compressorcomprising, a casing having an inlet cover formed with a peripheralflange and having a centrally disposed bearing means, a shaft journaledin said bearing means and including means outside of said casing forconnection to a motive source,

said inlet cover having for-med therein a semitoroidal circumferentiallyextending pumping duct having an inlet opening at one end and having aradially inwardly extending discharge passage at its opposite end, saidcasing further including an outlet cover formed with a peripheralflange, fastening means interconnect'mg said covers at said peripheralflanges to form said casing,

said outlet cover having formed therein a semitoroidal circumferentiallyextending pumping duct having an outlet opening at one end and radiallyinwardly extending inlet passage at its opposite end, and a generallydisk-shaped rotor having a driven connection with said shaft forrotation inside of said casing,

said rotor having semi-toroidal circumferentially continuous vane ductson opposite axial sides thereof disposed between said pumping ducts,each vane duct having a plurality of transversely extendingcircumferentially spaced vanes forming a plurality of impeller pocketsin said vane duct to pump fluid from the inlet to the outlet of eachrespective pumping duct,

and means forming an internal axial through passage in said rotorinterconnecting said radial discharge passage with said radial inletpassage,

thereby interconnecting said pumping ducts on opposite sides of saiddisk-shaped rotor in series flow staged relatron.

4. A reentry compressor comprising a casing having an inlet and anoutlet and a pair of axially spaced annular circumferentially extendingpumping ducts disposed therebetween,

a rotor in said casing having oppositely disposed impeller meansextending radially between and in register with said pumping ducts,

and axial passage means in said rotor interconnecting the dischargeportion of one of said pumping duets with the inlet portion of the otherof said pumping ducts,

thereby staging the tionship.

5. A rentry compressor comprising casing means having a pair of separatepumping chambers spaced axially from one another,

a rotor in said casing means extending radially between said pumpingchambers and having impeller means extending axially from opposite facesthereof to cooperate with each corresponding pumping chamber,

said casing means having an inlet opening to one of said chambers and anoutlet opening from the other of said chambers,

and internal passage means formed in said casing means and including apassage formed in and extending through said rotor axially andinterconnecting said chambers in series staging with one another.

6. A reentry compressor as defined in claim 5,

said rotor comprising a generally disk-shaped member having an enlargedperipheral portion formed with vane ducts on opposite axial sides,

each vane duct being substantially semi-cyclindrical in cross section toform a trough-shaped recess,

and a plurality of circumferentially spaced vanes extending radiallyacross said vane ducts to form plural impeller pockets.

7. A reentry compressor as defined in claim 6 and further characterizedby said pumping chambers in said casing means comprising pumping ductsessentially semicylindrical in cross-sectional configuration and beingdisposed in confronting registry with said vane ducts.

8. A reentry compressor as defined in claim 7 and further characterizedby said internal passage means comprising radially inwardly extendingpassages intersecting said pumping ducts and said axial through passageformed in said disk-shaped rotor inwardly of said peripheral portion ofsaid rotor.

9. A reentry compressor comprising casing means having a pair ofseparate pumping cham- =bers spaced axially from one another,

a rotor in said casing means having impeller means extending axiallyfrom opposite faces thereof to cooperate with each corresponding pumpingchamher,

said casing means having an inlet opening to one of said chambers and anoutlet opening from the other of said chambers,

and internal passage means formed in said casing means and extendingthrough said rot-or to stage said chambers in series with one another,

said rotor comprising a toroidally shaped article made of sheet formmaterial and shaped to include a plurality of struck out portionsforming impeller vanes with said internal passage means constitutingopenings underlying said vanes, thereby to additionally pressurize saidfluid as it passes through said passage means.

pumping ducts in series flow rela- 7 8 a 10. A reentry compressor asdefined in claim 9 whereof said rotor interconnecting said outlet ofsaid in said rotor has an axially extending wall and said first stagewith said inlet of said second stage, struck out portions are formed insaid wall. a said internal passage characterized by having 11. A fluidcompressor as defined in claim 10 wherein 7 formed therein pumping vanesto additionally said axial wall has a plurality of struck out portionscir- 5 pressurize the fluid passing therethrough.

cumferentially spaced to form openings and centrifugal pumping vanes forassisting in pressurizing the fluid pass- Referefices Cltgd y theExaminer 7 ing therethrough. UNITED STATES PATENTS 12. A fluidcompressor of the drag type comprising, 1973 669 (1/1924 Spoor casingrneans forming two pumping chambers cOn- 10 5 1 Thom E T "1034115stituting a first stage and a second stage, .j gf 7/3963 g et a; n 103each having an inlet and an outlet, f ifi 'is 6/ 964 S th n 1 103-96 andan impeller rotor journaled for rotation in said m1 casing means,FOREIGN PATENTS and having a centrally disposed hub, 15 858,956 3/1953Germany. a disk extending radially outwardly therefrom, 13,72 5 1892Gmat Britain and oppositely disposed vanes outwardly of said 7 disk foracting on fluid in each respective stage DQNLEY I, STOCKING, Primary E iof said two pumping chambers, K and an internal pasage extending throughsaid disk 20 h RADUAZO Exammer

1. A FLUID COMPRESSOR OF THE DRAG TYPE COMPRISING, CASING MEANS FORMINGTWO PUMPING CHAMBERS CONSTITUTING A FIRST STAGE AND A SECOND STAGE, EACHHAVING AN INLET AND AN OUTLET, AND AN IMPELLER ROTOR JOURNALED FORROTATION IN SAID CASING MEANS, AND HAVING A CENTRALLY DISPOSED HUB, ADISK EXTENDING RADIALLY OUTWARDLY THEREFROM, AND OPPOSITELY DISPOSEDVANES OUTWARDLY OF CORRESPONDINGLY OPPOSITE SIDES OF SAID DISK FORACTING ON FLUID IN EACH RESPECTIVE STAGE OF SAID TWO PUMPING CHAMBERS,AND AN INTERNAL PASSAGE FORMED IN AND EXTENDING AXIALLY THROUGH SAIDDISK OF SAID ROTOR AND INTERCONNECTING SAID OUTLET OF SAID FIRST STAGEWITH SAID INLET OF SAID SECOND STAGE.